Mr Patterson (pictured), the group’s chief executive, said he was “deeply disappointed” with the practices uncovered at BT Italy.

“The good progress we’re making across most of the business has unfortunately been overshadowed by the results of our investigation into our Italian operations and our outlook,” he said.

“This has no place at BT, and it undermines the good work we’re doing elsewhere in the group. We are committed to ensuring the highest standards across the whole of BT.

“We face a more challenging outlook in the UK public sector and international corporate markets but we’ve seen record growth at EE, strong momentum in consumer, and our highest ever fibre net connections in Openreach.”

'Pushing ahead with reforms'

He said improving the customer experience remained a top priority.

“EE is now answering 100% of its customers’ calls in the UK and Ireland. In Openreach, missed appointments have halved year on year.

“We’ll continue to invest to ensure our service levels improve and that our customers see the benefit.

“We are pushing ahead with reforms at Openreach, particularly on governance and customer service and continue to believe an agreement can be reached with Ofcom on its Digital Communications Review.

“We think these changes address Ofcom’s concerns and can form the basis for a fair, proportionate and sustainable settlement.”

Last week, BT confirmed a number of price increases, with the cost of standard broadband going up by £2 a month and fibre broabdand by £2.50 from 2 April.

It also announced that BT TV customers who currently get BT Sport for free will be charged £3.50 a month for the service from 1 August.